HR: 16:40h
AN: H54C-03 INVITED    [Abstracts]
TI: Effects of Aging and Colloids on Iron Nanoparticle Transport in Groundwater
AU: * Johnson, R L
EM: rjohnson@ebs.ogi.edu
AF: Oregon Health & Science University, 20000 NW Walker Road, Beaverton, OR 97006, United States
AU: Tratnyek, P G
EM: tratnyek@ebs.ogi.edu
AF: Oregon Health & Science University, 20000 NW Walker Road, Beaverton, OR 97006, United States
AU: Nurmi, J T
EM: jnurmi@ebs.ogi.edu
AF: Oregon Health & Science University, 20000 NW Walker Road, Beaverton, OR 97006, United States
AB: Most studies of manufactured nanoparticle transport in aquifer materials have used "fresh" particles in homogenous solutions. However, the role of particle aging and the presence of other colloidal materials may have a significant impact on mobility. We have examined both of these processes using reactive nano-iron particles (RNIP), dynamic light scattering, column studies, and deep-bed filtration theory. In the absence of colloidal materials, RNIP are rapidly removed from porous media by coagulation and attachment to aquifer materials (due in part to their magnetic properties). However, upon aging (in the presence of oxidants ranging in strength from water to carbon tetrachloride), the outer shell of the RNIP will be converted to oxides that are less magnetic and have very different surface charges that result in different sticking coefficients. The presence of colloids (both organic and inorganic) may modify the surfaces of aquifer materials and/or bind with the nanoparticles, and as a consequence, aggregation and sticking coefficients of the nanoparticles can also be significantly altered.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2007 Fall Meeting